Pipe pushing machine



Dec. 1, 1959. w. F.'HIXSON PIPE PUSHING MACHINE 2 Sheets-Sheet 1 Filed June 1, 1956 INVENTOR. WILLIAM F. HIXSON BY DES JARDINSQROBINSON 8. KEI SER HIS ATTORNE S Dec. 1, 1959 w. F.'H|XSON 2,915,282

PIPE PUSHING MACHINE Filed June 1, 1956 2 Sheets-Sheet 2 INVENTOR. WILLIAM F. HIXSON BY DES JARDINS, ROBINSON 8. KEISER HIS ATTORNEYS United States Patent PIPE PUSHING MACHINE William F. Hixson, Louisville, Ky.

Application June 1, 1956, Serial No. 588,733

'10 Claims. (Cl. 254-29) This invention relates to a machine for pushing pipes or conduits underneath roads or other earthen structures and, more particularly, to a machine which is operated by compressed air and functions automatically to push a length of pipe through the earth.

My invention represents an improvement over previous machines adapted for pushing pipe through the earth in that it is faster in operation, requires less attention on the part of the operator, and is more powerful for its size 'aii-d'weight than the prior art devices. My device is adapted to be operated by compressed air which is gen erally available wherever construction work is going on.

The air driven mechanism operates automatically and Will push an entire length of pipe beneath a road or other earthen structure before any intervention on the part or the operator becomes necessary. After-a full length ofpipe has been thus pushed into place, another length ofpipe may be coupled thereto and the operation continued to automatically push the double length of pipe into the soil. This procedure may be repeated for as many lengths of pipe as are required to complete the i 1 My improved machine is of simple and sturdy con- 'struction and is provide-d with a pair of double-acting air cylinders which furnish sufiicient power to push the pipe through the hard and firmly compaced soil customarily found beneath road beds.

Accordingly, it is an object of my invention to provide a power operated pipe pushing machine which is adapted to automatically push a complete length of pipe into the earth beneath a road or other earthen structure.

Another object of my invention is to provide an improved form of power clamping and power driving mechanism for a pipe pushing machine which mechanism is cyclically operable to produce a step-by-step feeding {movement-of the pipe as it is pushed into the soil.

-'Another-object of the present invention is to provide anew and improved form oflinkage for effecting the one-already driven and the carriage thereafter adjusted on. the, base so as to locate the clamping jaws behind the coupling andenable the new section to be automatically pushed into the ground behind the preceding section.

With these and other objects in view, which will become apparent from the following description, the invention includes certain novel features of construction and combinations. of parts, the essential elements of which are set forth in the appended claims and a pre ferred form or embodiment of which will hereinafter be described with reference to the drawings. which accompany and form a part of this specification.

In the drawings:

Fig. 1 is a plan view of my pipe pushing machine ice in which the pipe being pushed thereby is shown in phantom outline.

Fig. 2 is a side view of the machine shown in Fig. l with parts of the base broken away to reveal the .pipe pushing mechanism.

Fig. 3 is a cross-sectional view taken along the line 3 3 in Fig. 1 with parts broken away to show the pushing mechanism. I

Fig. 4 is a schematic view of the pneumatic system of the machine.

Fig. 5 is a diagrammatic View showing the two positions of the carriage on the base.

Similar reference characters designate similar or identical elements and portions throughout the specification and throughout the different views of the drawings.

My improved pipe pushing machine consists essentially of two principal parts, a base 10 and a carriage 11 supported thereon for longitudinal sliding movement. As shown, the base 10 is of simple construction, being formed of a pair of side rails 12 which provide guideways for the carriage and are supported in spaced relation by three cross rails 13 welded thereto. The rails 12 and 13 are preferably formed from aluminum angle stock so as to provide a light-weight sturdy base for the machine.

The carriage 11, which contains the pipe pushing mechanism per se, includes an aluminum frame which consists essentially of a pair of vertical end plates 16 and 17 which are held in spaced relation by four tie bolts 18 located at the four corners of the plate, and spacer sleeves 19 placed on the bolts between the end plates .16 and 17 to provided the proper spacing therebetween.

The end plates 16 and 17 are further connected by four additional tie bolts 23 (see Fig. 3) which pass through and provide support for, a link mounting block 20. The block 20 is located intermediate the end plates by a set of spacer sleeves 21 which are received on the tie bolts 23 between the block 28 and the end plate 17. A second set of spacer sleeves 22 situated on the bolts between the block 20 and the end plate 16 serve to hold the block 20 in place between the end plates and to provide further rigidity to the carriage frame.

The end plates 16 and 17 are each provided with a circular aperture 24 (see Fig. 3) which is centrally located in each of the plates and is in longitudinal alignment with a similar aperture 25 provided in. the block 20. These apertures are designed to receive and support a conduit or pipe 26 which is to be pushed into the earth by the machine. For this purpose, the apertures 24 and 25 should, of course, be somewhat larger than the largest size of pipe which is to be pushed by the machine.

Pushing of the pipe 26 is etfected by a pair of clamp ing jaws 30 provided with cylindric pipe engaging surfaces which are preferably provided with serrations 31 in order to improve the bite of the jaws on the pipe.

To accommodate the machine to pipes of different diameters, it is furnished with a plurality of sets of jaws 30 of differentsizes to correspond with the various pipe sizes to be pushed by the machine. For this purpose, as shown in Fig. 3, each jaw is provided with apairof spaced mounting lugs 32 which are apertured to receive a pivot pin 33 having a bentover portion 34; (Fig; 1,). at its upper end to facilitate its removal and replacement in. the apertures provided in the lugs 32 whenever a different set of jaws is required. Each jaw is pivoted by the pin 33 on the inner end of a lever 35 which, in turn, is pivoted on a pin 36 extending between a pair of spaced apart arms 37. Each pair of arms 37 is, provided-fiat its outer end with a pad 33 which is Welded to the'side edges of the arms so as to maintain them. in spaced apart relation. At its inner end, each pair of arms 37 is piv- 3 oted on a pin 39 which is received in apertures provided in a pair of spaced apart lugs 40 formed integrally with the block 20.

The levers 35 carrying the jaws 30 are thus supported by the arms 37 for movement toward and away from the pipe 26 as the arms are turned about their pivot pins 39. Feeding movement of the jaws in the longitudinal direction is efiected by turning the levers: 35 about their pivot pins 36. This movement of the levers 35 is effected by a pair of double-acting air cylinders 45 which are supported on the end plate 17 for pivotal movement about a vertical axis by means of pivot pins 46 (Figs. 1 and 2) which pass through apertured lugs 47 provided on the cylinders and corresponding lugs 48 provided on a bracket 49 secured to the plate 17. Each cylinder is provided with a piston rod 50 which has secured to its outer end a clevis 51 which is pivotally connected by a pin 52 with the outer end of its associated lever 35. Hence, inward and outward movement of the levers 35, due to rocking of the arms 37, is permitted by reason of the pivoting of the air cylinders 45 on the pins 46.

Inward movement of the jaws 30 into clamping engagement with the pipe 26 is effected by a pair of singleacting air cylinders 55 which are suitably supported on a frame plate 56 attached to the end plate 16. Each cylinder 55 is provided with a piston rod 57 which is adapted to bear against the pad 38 of its associated arm 37. Hence, when air is supplied to the cylinders 55, their piston rods 57 will be projected outwardly to press the outer ends of arms 37 inwardly and thereby cause the jaws 30 to be forcibly clamped against the opposite sides of pipe 26. When the piston rods 50 of the air cylinders 45 are now projected outwardly by the application of air to the outer ends of the cylinders, the jaws 30 will he moved toward the right and the pipe 26 will be pushed in the direction of the arrow 58 (Fig. 1). Thereafter, air is released from the cylinders 55 to release the jaws 30 and air is supplied to the inner ends of cylinders 45 to retract the piston rods 50 and thereby restore the jaws 30 to their original starting positions.

The flow of air under pressure to the cylinders 45 and 55 is controlled by a balanced reversing valve 60 which is secured by bolts 59 to an angle 62 secured to the upper edge of plate 17. The valve and its connections to the air cylinders may be best understood by referring to the schematic layout of the pneumatic system shown in Fig. 4 of the drawings. As there illustrated, air under pressure is supplied from an air compressor or other suitable source through a supply line 61 which is connected to the inlet port of the valve 60 through a cutolf valve 62. The high pressure air is delivered to the ends of the valve through ducts 63 and to the center of the valve through a duct 64. The valve is provided with a spool 65 which is movable to either of two positions within the cylindric chamber provided in the valve body. When the spool is in the position shown in Fig. 4, high pressure air from the duct 64 will be delivered through pipe 66 and flexible hoses 67 to the forward ends of cylinders 45 so as to cause the piston rods 50 thereof to be retracted. At the same time, the rear ends of the cylinders 45 will be connected by flexible hoses 68 and a pipe 69 with an exhaust port 75) provided in the valve 60. This will permit air in the rear ends of the cylinders to escape as the piston rods are retracted. In this setting of the valve, the single acting cylinders 55 will likewise be connected with the exhaust port 70 through conduits 71 which are communicatively connected with the pipe 69. Suitable return springs within the cylinders 55 will cause the piston rods 57 thereof to be retracted and thereby release the clamping jaws from the pipe 26.

When the spool 65 of the valve is moved to its other position in which the spool lies in its lowermost position within the valve chamber, air under pressure from the duct 64 will be supplied through the pipe 69 and hoses 68 to the rear ends of the cylinders 45 thereby causing the piston rods 56 to be projected outwardly. At the same time, air in the forward ends of the cylinders will be permitted to escape through the hoses 67 and pipe 66 to atmosphere through a relief port 72 provided in the valve. Air under pressure will also be supplied through the conduits 71 to the cylinders 55 to thereby move the piston rods 57 outwardly so as to cause the clamping jaws 30 to be forced against the pipe 26, and grip it tightly as the jaws are moved to the right, as viewed in Fig. 1, by outward movement of the piston rods 50.

Movement of the valve spool 65 between its two positions within the valve body is controlled by a pair of poppet valves 75 which are supported on and adjustable along a horizontal bar 76 which is secured to the end plate 17. Each poppet valve is connected by a flexible hose 77 with a port on the valve body which communicates with the end of the valve chamber provided therein. The poppet valves 75 are adapted to be actuated by a circular disk 7 8 which is supported for sliding movement on the piston rod 50 of one of the air cylinders 45. A pair of centering springs 79 mounted on the piston rod 50 on either side of the disk 78 tend to hold the disk resiliently in a centered position on the piston rod.

When the piston rod 50 carrying the disk 78 is retracted inwardly on the return stroke of the clamping jaws, the right-hand poppet valve (Figs. 2 and 4) will be contacted by the disk 78 as the piston rod 50 approaches the end of its stroke. The poppet valve will thereby be opened so as to cause venting of the lower end of the valve chamber beneath the spool 65 and permit the spool to be moved to its lower position by high pressure air acting on the upper end of the spool. The operation of the cylinders 45 and 55 will thereby be reversed and the piston rods of the cylinders 45 will be projected outwardly to produce a working stroke of the jaws 30. As the piston rods approach the outer ends of their strokes, the disk 78 will contact the left-hand poppet valve 75 (Figs. 2 and 4) and vent the upper end of the valve body to atmosphere. The spool 65 will now be shifted upwardly to the position shown in Fig. 4 and the piston rods 50 will be retracted and the clamping jaws released so as to return the jaws to their starting positions ready for the next stroke of the pushing apparatus. Hence, so long as the valve 62 remains open to permit high pressure air from the supply line 61 to enter the valve 60, the jaws 30 will continue to feed the pipe 26 step-by-step toward the right as viewed in Fig. 1. The entire length of pipe 26 will thus be automatically driven into the earth, ample force being provided by the power furnished by the two large air cylinders 45 and the positive clamping of the jaws 30 against the pipe.

As shown in Fig. 1, the tendency of the carriage 11 to move to the left under the influence of the thrust produced on the pipe 26 by the jaws 30 is prevented by an abutment element 80 which may consist of a railroad tie laid crosswise of the trench in which the pipe pushing machine is located. The left-hand end of the base 10 abuts the forward edge of the member 80 and the carriage 11 likewise bears against the forward face of the abutment member to thereby block the carriage against movement toward left as viewed in Figs. 1 and 2 during the pipe pushing operation. When the full length of pipe 26 has been pushed into the earth and the jaws 30 approach the end of the pipe, the carriage 11 is slid to the right on the base 10 along the guideways afforded by the angle-shaped side rails 12. A bar 81 is then dropped into a pair of transversely aligned slots 82 cut in the vertical webs of the rails 12 as shown in the left-hand illustration in Fig. 5. The bar 81 will thus lie behind the carriage 11 and trans mit the reaction from the carriage to the base 10 which, in turn, transmits it to the abutment element 80. Automatic pushing of the pipe is again commenced by opening valve 62 and is continued until the end of the pipe again approaches the jaws 30. Pushing is then stopped and the carriage 11 is again returned to the left as indicated in the right-hand illustration of Fig. 5. A new length of pipe is then coupled to the length which has been pushed into the earth and the pushing operation is continued by again opening the valve 62 to cause automatic clamping and feeding movement of the jaws 30.

While I have described my invention in connection with one possible form or embodiment thereof and have used, therefore, certain specific terms and language herein, it is to be understood that the present disclosure is il' lustrative rather than restrictive and that changes and modifications may be resorted to without departing from the spirit of the invention or the scope of the claims which follow:

I claim:

1. An automatic pipe pushing machine comprising a base, transversely spaced-apart longitudinally extending guideways on said base, a carriage mounted for longi tudinal sliding movement on said guideways, a poweroperated pipe pushing mechanism fulcrumed upon the base for being levered relative thereto, and means at opposite sides of said base defining a plurality of longitudinally spaced-apart fixed positions of carriage thereon in which the carriage may be held during pipe pushing operations, the means for one of the fixed positions being at the end of the base.

2. The pipe pushing machine of claim 1 wherein said defining means includes a pair of transversely aligned abutment surfaces on said base.

3. The pipe pushing machine of claim 1 wherein said defining means includes a pair of transversely aligned slots formed in said guideways.

4. An automatic pipe pushing machine comprising a frame, a pair of pipe clamping jaws supported on said frame for transverse movement to enable said jaws to be engaged with opposite sides of said pipe and to clamp the same therebetween, said jaws also being fulcrumed upon said frame for longitudinal movement relative to said frame in order to push the pipe in the direction of its length, and cyclically operable means for giving the pipe a step of forward movement on each cycle of operation,

said means including a power operated mechanism for simultaneously engaging said jaws with said pipe and moving said jaws longitudinally to push the pipe forward, and for simultaneously disengaging said jaws and moving them rearwardly along the pipe back to their starting positions in readiness for the next cycle of operation.

5. The automatic pipe pushing machine of claim 4 wherein said power operated mechanism includes a first fluid pressure motor for moving said jaws transversely, and a second fluid pressure motor for moving the jaws longitudinally, and said cyclically operable means includes a reversing valve and means controlled by the longitudinal movement of said jaws for actuating said valve.

6. An automatic pipe pushing machine comprising a base, transversely spaced-apart longitudinally extending guideways on said base, a frame for longitudinal sliding movement on said guideways, a pair of pipe clamping jaws disposed on opposite sides of the pipe to be pushed, means for supporting said jaws for both transverse clamping movement and longitudinal feeding movement on said frame, said means including a pair of clamping arms extending lengthwise of the pipe and pivoted at one end on said frame to enable the free ends thereof to be moved toward and away from the pipe, and a pair of feeding -levers each pivoted intermediate its ends on one of said arms and each carrying one of said jaws at its inner end, whereby said jaws may be engaged with the pipe by moving the free ends of said clamping arms relative to the pipe, and said jaws may be given longitudinal movement by turning said levers about their pivots on said arms.

7. The automatic pipe pushing machine of claim 6 in- Cluding power operated means for moving the free ends of said arms relative to the pipe to engage the jaws therewith and for turning said levers about their pivots on said arms to move the jaws longitudinally relative to said frame.

8. The automatic pipe pushing machine of claim 7 wherein said power operated means includes a first pair of fluid pressure motors for moving the free ends of the arms relative to the pipe to engage the jaws with the pipe, and a second pair of fiuid pressure motors for turning said levers about their pivots on said arms to move the jaws longitudinally relative to said frame.

9. The automatic pushing machine of claim 8 including a reversing valve for controlling both pairs of motors in synchronism to cause cyclical operation of the machine, said valve in one position causing the jaws to be engaged and moved forwardly to feed the pipe, and in another position to cause the jaws to be disengaged and returned to their starting positions.

10. The pipe pushing machine of claim 9 including means for automatically shifting said valve from one of said positions to the other at the end of the forward and reverse strokes of said jaws in the longitudinal direction to produce automatic cycling of the machine and step-bystep feeding of the pipe.

References Cited in the file of this patent UNITED STATES PATENTS 2,056,489 Scott et al Oct. 6, 1936 2,080,104 Abramson et al May 11, 1937' 2,591,859 Otis Apr. 8, 1952 2,685,430 Henke Aug. 3, 1954 2,764,133 Pegard Sept. 25, 1956 

